efi/gop: Slightly re-arrange logic of find_gop

Small cleanup to get rid of conout_found.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200320020028.1936003-6-nivedita@alum.mit.edu


Signed-off-by: Ard Biesheuvel <ardb@kernel.org>